熊果酸对IL-6介导的乳腺癌细胞侵袭与迁移的抑制作用

Inhibitory effects of ursolic acid on IL-6-mediated invasion and migration of breast cancer cells

目的 探讨熊果酸对白细胞介素6(IL-6)介导的乳腺癌MDA-MB-231细胞(简称“231细胞”)的侵袭与迁移的抑制作用。方法 采用CCK-8法检测20、40、80、160、320μmol/L熊果酸对231细胞增殖率的影响。将细胞分为对照组、模型组和给药组,划痕实验与Transwell实验检测细胞的迁移能力与侵袭能力;实时荧光定量聚合酶链式反应(q-PCR)法与Western blot法检测细胞上皮间质转化相关标志物E钙黏蛋白(E-cad)、基质金属蛋白酶2(MMP2)、MMP9、波形蛋白(Vim)、CD44分子(CD44)、醛脱氢酶1家族成员A1(ALDH1A1)mRNA与蛋白的相对表达情况;Western blot法检测Janus激酶2/信号转导及转录激活因子3(JAK2/STAT3)通路中JAK2、STAT3的磷酸化水平[以磷酸化JAK2(p-JAK2)/JAK2比值、磷酸化STAT3(p-STAT3)/STAT3比值计]。结果 实验选取熊果酸低浓度20μmol/L(对细胞增殖能力无明显抑制作用)作为后续给药浓度。与对照组比较,模型组细胞的迁移、侵袭能力均显著增强(P<0.05);与模型组比较,给药组细胞的迁移、侵袭能力均显著降低(P<0.05)。与对照组比较,模型组细胞中上皮间质转化相关标志物MMP9、MMP2、Vim、ALDH1A1、CD44 mRNA与蛋白的相对表达量均有不同程度的升高,E-cad mRNA与蛋白的相对表达量均有不同程度的降低,部分差异有统计学意义(P<0.05),p-JAK2/JAK2比值、p-STAT3/STAT3比值均显著升高(P<0.05);与模型组比较,给药组细胞中上述指标的表达均有一定程度逆转。结论 熊果酸通过阻断JAK2/STAT3信号通路的激活进而抑制炎症因子IL-6诱导的上皮间质转化过程,最终抑制乳腺癌细胞的侵袭、迁移。

OBJECTIVE To investigate the inhibitory effects of ursolic acid on interleukin-6(IL-6)-mediated invasion and migration of breast cancer MDA-MB-231 cells(hereinafter referred to as“231 cells”).METHODS The effects of 20,40,80,160 and 320μmol/L ursolic acid on the proliferation rate of 231 cells were measured by CCK-8 method.The breast cancer 231 cells were divided into control group,model group and administration group.The migration and invasion abilities of cells were detected by scratch assay and Transwell assay.Real-time quantitative polymerase chain reaction(q-PCR)assay and Western blot assay were used to detect the mRNA and protein expressions of epithelial-mesenchymal transition-related makers such as E cadherin(E-cad),matrix metalloprotein 2(MMP2),MMP9,vimentin(Vim),CD44 molecule(CD44)and aldehyde dehydrogenase 1 family member A1(ALDH1A1).The phosphorylation levels of JAK2 and STAT3 in the Janus kinase 2/signal transducer and activator of transcription 3(JAK2/STAT3)signaling pathway(in terms of p-JAK2/JAK2 ratio and p-STAT3/STAT3 ratio)were detected by Western blot assay.RESULTS A low concentration of ursolic acid of 20μmol/L(no significant inhibitory effect on cell proliferation ability)was selected as the subsequent administration concentration.Compared with the control group,the migration and invasion abilities of cells in the model group were significantly enhanced(P<0.05);compared with the model group,the migration and invasion abilities of cells in the administered group were significantly reduced(P<0.05).Compared with the control group,the relative mRNA and protein expressions of epithelial-mesenchymal transition-related markers MMP9,MMP2,Vim,ALDH1A1 and CD44 were all elevated to different extents,and the mRNA and protein expressions of E-cad were all decreased to different extents in the model group cells,and part of the differences had statistical significance(P<0.05),the p-JAK2/JAK2 ratio and p-STAT3/STAT3 ratio were significantly increased in the model group(P<0.05);compared with the model group,the expressions of the above indicators were reversed to some extent in the administration group.CONCLUSIONS Ursolic acid blocks the activation of JAK2/STAT3 signaling pathway and thus inhibits the epithelial-mesenchymal transition induced by the inflammatory factor IL-6, which ultimately interrupts the invasion and metastasis of breast cancer cells.